Beech Trees and Snails

Their dense canopy makes beech trees ideal for shade.

Beech trees (Fagus spp.) are deciduous trees grown for their grayish-silver bark and dense canopy. Depending on the species, beech trees grow in U.S. Department of Agriculture plant hardiness zones 3 through 9. The beech tree is no stranger to pests and can come under attack by snails. Typically, a healthy beech tree can withstand a snail infestation, which proves to be more of an annoyance than a real threat. However, snails can still damage the tree and should be controlled if their numbers rise.

Snails and Trees

Snails can infest just about any type of tree. However, some snails prefer a hollow beech tree. Most species of beech trees tend to become hollow as the tree ages. This is typically caused from a fungal disease that results in wood decay. A hollow trunk doesn’t mean the tree will die, though it does make the beech more susceptible to storm damage. The American beech (Fagus grandifolia) frequently becomes hollow at the tree’s butt, the thickest part of the trunk. Various wild creatures benefit from hollow trees by using them for shelter and cover. Snails chew irregular-shaped holes in the foliage of plants such as beech trees. They consume living plants as well as decaying plant matter. Snail damage can be confused with damage caused by caterpillars, earwigs or other chewing pests. To pinpoint the culprit, look for silvery trails on the beech tree. These trails are a sure sign that snails are attacking the tree.

Snail Baits

Various types of snail baits are available and help control these slow-moving pests. Metaldehyde is the main ingredient in many snail baits and works best during warm weather. Once the snails consume the bait, which is in pellet form, they dehydrate and die within 24 hours. However, baits containing metaldehyde are toxic to dogs, cats and wildlife and should never encounter vegetables or plants. A safer option is to use snail baits with iron phosphate as the main ingredient. Iron phosphate snail baits don’t pose a risk to children, pets, birds or fish and can be scattered around plants, lawns and gardens. The downside to iron phosphate baits is that it takes longer -- typically several days -- for the snails to die than with metaldehyde baits.

Snail Barriers

Copper barriers protect plants from snail damage without harming the snail. When placed around the beech tree, the copper bands or strips react with the slime that snails naturally produce and deliver an electric shock. Unfortunately, if any debris, such as a leaf, lands on the copper barrier, the snail can use the debris as a way to move across the copper without receiving the electric shock. If copper barriers are used to deter snails, regular inspection to remove debris is needed to increase the effectiveness of the copper.

Considerations

Eliminating the ideal environment for snails helps keep their numbers under control. For example, snails hide under debris such as boards, stones, fallen plant matter and weeds. By removing these hiding places, you reduce the chance of a snail infestation. Snails thrive in humid conditions that can occur with poor irrigation. Replacing sprinkler irrigation with drip irrigation reduces the humidity level, creating a dryer environment that many pests, including snails, don’t like. Using these suggestions in conjunction with snail baits or barriers helps provide complete protection against these annoying pests.